There are instances of erectile impotence in which the patient does not respond to more conventional therapy and the surgical implanting of a penile prosthesis may be the only practical means of remedying the impotency.
Several types of penile prostheses have been employed in the past. One type of penile prosthesis is a pair of rods of suitable stiffness which are surgically implanted into the corpus cavernosum of the penis. One disadvantage of some of the rod-type implants is the permanent stiffness of the rod which can be a source of physical pain and/or embarrassment to the patient. The prostheses disclosed in U.S. Pat. No. 3,893,456 and U.S. Pat. No. 4,066,073 are representatives of the rod type prostheses.
Another type of penile prosthesis which is available is the inflatable prosthesis of U.S. Pat. No. 3,954,102. The patented prosthesis includes two fairly long inflatable and distensible tubes that are surgically implanted in the corpus cavernosum of the penis. Each of the two tubes is connected by tubing to a pressure bulb of inflating fluid which is implanted elsewhere in the body. Because of the volume required to inflate, distend, pressurize and rigidize the inflatable tubes, the pressure bulbs can be relatively large.
Recently penile implants have been patented which are cylinders systems which are adapted to be implanted in the corpora of the pendulous penis. These cylinders each contain a hydraulic system consisting of a pressure chamber, a reservoir for pressurizing fluid and a pump for transferring the fluid from the reservoir to the pressure chamber to make it rigid. Representative of such implants are those of U.S. Pat. Nos. 4,353,360, 4,267,829 and 4,383,525.
Although the previously patented prostheses are useful and valuable devices, there is still a need for improved penile implants.